The renowned composer/conductor Pierre Boulez was an iconic figure in 20th century music – he encouraged composers to break free from traditional methods and to let their imagination run riot. He supported such avant-garde moves as electronic music and pioneered a development of Schoenberg’s 12-tone technique. Boulez wanted to throw out the traditional rule book – he championed what he called “controlled chance” when musicians were given choices about how to perform music which Boulez had written. Music should be “a labyrinth with no fixed route” he said and once said that classical music’s history “seems more than ever to me a great burden. We must get rid of it once and for all”.

Boulez was a delightful maverick: in 1967 he suggested that all the opera houses in the world “should be blown up”. That did not stop him conducting opera – most famously The Ring Cycle at Bayreuth – but he had an immense influence on music and musicians. From the Ircam Studios he created in the Centre Pompidou in Paris he inspired a new generation of musicians and composers to reconsider contemporary music: “We need to,” he said, “restore the spirit of irreverence in music.”

As a conductor, Boulez appeared with most of the world’s greatest orchestras, leading the BBC Symphony Orchestra from 1971 to 1975 and the New York Philharmonic from 1971 to 1977.

Scotland witnessed many performances by Boulez – at no fewer than 11 Edinburgh Festivals. He first came in 1948 with the Renaud-Barrault Theatre Company directing the music for their production of Hamlet. His concerts in the Usher Hall saw Boulez in typically challenging form. No more so than in 1984 when he conducted the BBC Symphony Orchestra with Jessye Norman as soloist in a concert that included music by Berg, Bartok and his own Notations. It was deemed the highlight of the Festival.

Pierre Boulez was born in Montbrison, near Lyon, the son of an industrialist growing up in Nazi-occupied France. He studied composition and the piano from 1942 with Olivier Messiaen at the Paris Conservatoire. He displayed an early talent as a composer and his Marteau Sans Maître (Hammer Without a Master) was acclaimed by critics. The music cunningly married the traditions of Vienna with a sparkling French finesse.

In 1960 he conducted the premier of his epic Pli Selon Pli which was scored for a soprano and percussion to the poems of Stéphane Mallarmé.

As he concentrated more on conducting Boulez became associated with drawing from orchestras a very particular sound. He had an extremely sensitive ear for the balance in an orchestra and insisted that a disciplined rhythm and a clear sound be realised as he rehearsed. When Boulez conducted a new production of Pelléas et Mélisande at Covent Garden in 1969, he tuned each section of the orchestra repeatedly before he entered the orchestra pit. He was a meticulous and scrupulous musician who had an acute and perceptive ear.

At both the New York Philharmonic and the BBC Symphony Orchestra he set about modernising their repertoire and distancing the programming from conventional formats. He wanted to make orchestras appeal to younger audiences and play music of their time – in London he held concerts in the Roundhouse in north London. Boulez conducted several Proms with the BBC Symphony (but refused to get involved in the Last Night) but there is no doubts that his time with the orchestra opened doors for many (not least the orchestra) and introduced a new public to modern music.

In the late 1960s he accepted offers from opera houses – but only works that interested him: Parsifal at Bayreuth and Wozzeck in Frankfurt then the centenary Ring Cycle at Bayreuth in 1976. It was a mammoth undertaking – all four operas premiered in a week and Boulez brought a grand majesty to the highly charged scores.

The production was filmed and John Boundy (former Head of Arts on Radio4) worked on the filming. “Boulez was a charming relaxed man - almost laidback,” he told The Scotsman yesterday. “Always easy to deal with and invariably courteous. I would go and collect him and inform him we were ready to film and there he was in his private room reading a book on the history of architecture drinking a cup of tea. He was an intellectual without any hint of histrionics. When he got to the podium he was totally in control and the complete musician.”

Other historic events with which he was associated was the premier of the complete Lulu in 1979 in Paris.

Boulez somewhat mellowed in later years and became an ardent champion of Bruckner, Mahler, Stravinsky and Ravel – many of whose works he triumphantly recorded.

He remained a very private man and never talked about his personal life.